This Invention relates to insecticidal compositions and methods of using same to control various crawling and flying insect pests, and relates more particularly to synergistic "poison-free" insecticides adapted to unexpectedly increase insect mortality and reduce kill time.
Commercially available insecticides, including those available for home use, commonly comprise active ingredients or "poisons" which are not only toxic to the target insect pests, but, if used in relatively confined environments and delivered as aerosol sprays, can be present in sufficient concentration to also be toxic to humans and household pets. Various undesirable side effects may include immediate or delayed neurotoxic reactions, and/or suffocation. Even the noxious odor of such materials can cause headaches or upset stomachs in some individuals. These adverse side effects are exacerbated when such compositions come in contact with persons of increased sensitivity, or persons of small body mass such as children or babies.
For some time, efforts have been made to develop insecticidal compositions, particularly those intended for residential use in aerosol form, which are effective in killing the targeted insect pests completely and quickly, but non-toxic to humans and pets. The Environmental Protection Agency (EPA) regulates the use of potentially toxic ingredients in pesticidal compositions under the Federal Insecticide, Fungicide and Rodenticide Act. Certain materials have been deregulated by the EPA or otherwise identified as acceptable "safe" substances offering minimum risk in normal use. Such substances are generally considered "poison-free" by the consumer. Thus, the term "poison-free" or "nonpoisonous" as used herein is intended to convey a composition that, while highly effective in killing targeted insect pests, is safe to use around humans, particularly small children, and pets.
Unfortunately, "poison-free" insecticidal compositions available heretofore incorporating deregulated materials as the active ingredient have had limited efficacy. Attempts to use deregulated essential oils as the active ingredient in such insecticides, while having limited success, have generally been found to be either cost prohibitive, inadequately lethal to control a range of targeted insect pest species, or too slow-acting to enable the user to confirm that the insect has been killed and to dispose of the dead insect so as to avoid polluting the environment.
Among the insects which are found to be particularly undesirable are cockroaches, both the American and German species. These pests shed their "skin" which, over time, disintegrates forming what is known as "cuticle" in the air, a particular problem for people suffering from asthma. Thus, not only is it important to kill cockroaches with an effective insecticide, the kill time must be sufficiently short for the carcass to be properly disposed of before the insect can crawl into a remote area to die.
While cockroaches are a prime target for a household spray, for general application such materials must also be effective against other crawling insects, such as ants, water bugs, silverfish, crickets, spiders and centipedes. Additionally, aerosol compositions of such insecticides of proper concentration must also be effective against various flying insects, including flies, mosquitoes, gnats, moths, wasps, hornets, yellow jackets and other bees, both inside and outside of the house.
Among the materials exempted by the EPA is cornmint oil (also known as Japanese mint or Mentha arvensis). Cornmint oil includes a high concentration of menthol and is known to contain alpha-pinene, myrcene, limonene, gamma-terpenine, 3-octanol, menthofuran, beta-caroyophyllene, germa-crene D and beta-pinene, along with other components. As with other mint oils, cornmint oil has been used as a flavorant in mouthwashes, cough syrups, throat lozenges, chewing gum, and the like.
While cornmint oil has been considered, along with many other essential oils, for its insecticidal or insect repellent properties, it has not been shown to be particularly effective, and certainly has not been distinguished from other materials of this kind as a candidate for special attention.